Hair treatment agent compositions having so-called conditioning effects which endow hair with smoothness and gloss and make combing easier are commonly sold in the markets under names such as “hair rinse”, “hair treatment”, “hair conditioner”, and “hair pack”.
A quartenary ammonium salt is blended in many of these hair treatment agent compositions as a main ingredient; it is adsorbed onto hair to give the aforementioned conditioning effects, which is a publicly known fact.
A practice of blending in a higher alcohol to form a gel-like complex with the quarternary ammonium salt and even adding liquid oils, waxes, silicone compounds, and natural and synthetic polymers as necessary is also publicly known.
However, when conventional hair treatment agent compositions are used, while smoothness and such can be given to the hair without causing stickiness at the time of application and during rinsing, satisfactory smoothness and ease of arranging the hair are hard to come by at the time of towel drying after rinsing, during hair drying, and after drying.
Also, since many of the aforementioned hair conditioning agents use a complex of a quarternary ammonium salt and a higher alcohol for the conditioning ingredient, the viscosity of the prepared product is determined by the contents and blend ratios of these, which puts many restrictions on recipes; adjusting the viscosity to the desired level while also adjusting the sensation during use is very difficult.
In addition, the aforementioned complex of the quarternary ammonium salt and the higher alcohol varies in its structure, i.e. lamella-vesicle, depending on the preparation method; this makes it difficult to adjust the viscosity to a fixed level; not only that, the temperature dependence of the viscosity of a hair conditioning agent containing such a complex is closely related to the melting point of the complex and, specifically, a steep reduction in the viscosity is observed at temperatures near the melting point, which is accompanied by a steep reduction in the stability of the product.
On the other hand, if, for purposes of solving the aforementioned problems, a thickener, such as a so-called polymer thickener commonly used in cosmetics including carboxyvinyl polymer and xanthan gum, is blended in these hair treatment agent compositions then various troubles arise. For example, since many of these polymer thickeners are anionic polymer electrolytes, they form a complex with the cationic surfactant contained in the hair conditioner and cause precipitation,which is not desirable for the stability and appearance of the product. Also, if a polymer thickener other than the anionic ones is blended in, an undesirable sensation during use occurs after rinsing-off, such as sliminess, which is characteristic of polymers.
Recently, a sensitive engineering method has been adopted for evaluating product characteristics during makeup application, and various factors have been found to be related to consumers' taste for the products. Particularly regarding hair conditioning agents, various investigations have been conducted to improve the tactile sensation during rinsing, after towel drying, and after drying; the aforementioned new investigation method has revealed that consumers pay significant attention to the tactile sensation when putting the product on their hands and to the experience of applying and spreading it on their hair. In such a process, adjusting the fluid flow characteristics (rheological characteristics) of the product to the consumers' liking becomes important. For this purpose, a hair treatment agent composition with proper viscosity and fluid flow characteristics is desired.
In view of the aforementioned problem, the inventors conducted earnest research and discovered that a composition comprising a cationic surfactant and hydrophobically modified polyether urethane which can associate in a water sobluble medium to increase the viscosity of the water soluble medium can solve the aforementioned problems and exhibits superior performance as a hair treatment agent composition, thus completing the present invention.
The object of the present invention is to provide a hair treatment agent composition which has good temperature stability in terms of viscosity, exhibits superior fluid flow characteristics, achieves smoothness and ease of arranging the hair after drying, and gives a superior sensation during use.
In the field of cleaning agents, many products are found in the market in the form of, for example, hair shampoo, body shampoo, face washing agents, etc. which have had their viscosity adjusted for ease of handling by adding a suitable thickener to a surfactant solution.
Usually, a few percent to a few tens of percent of a surfactant, mainly an anionic surfactant solution, is blended into these products for the purpose of adequate foaming and stain removal; in order to thicken a highly concentrated anionic surfactant solution, typically an ampholytic surfactant, cationic surfactant, and/or lipophilic nonionic surfactant, and/or the addition of a salt such as sodium chloride is combined in to promote micelle growth and thicken the system.
However, some anionic surfactants, such as N-acylmethyl taurate, N-acyl taurate, N-acyl isethionate, fatty acid soaps, and amino acid type surfactants, do not grow micelles easily even with addition of the aforementioned additives; as a result, giving sufficiently satisfactory viscosity to the product is difficult.
When the desired viscosity cannot be obtained, problems such as dripping occur during use; not only that, the feel during the use of the product, which recent consumers regard as very important, including sensory characteristics such as a rich sensation from adequate viscosity and ease of spreading, is difficult to satisfy, and therefore it is very difficult to receive high appreciation in the market.
On the other hand, if a thickener, such as a so-called polymer thickener commonly used in cosmetics including carboxyvinyl polymer and xanthan gum, is blended in these cleaning agent compositions then various troubles arise. For example, when these polymer thickeners are blended in, foaming, which is regarded as the most important characteristic of a cleaning agent, is hindered; furthermore, the foam once formed becomes easy to break, resulting in problems in the durability of foam and such. Also, if a polymer thickener is used, an undesirable sensation during use occurs after rinsing-off, such as sliminess, which is characteristic of polymers. Furthermore, in a highly concentrated surfactant solution, the surfactant acts as a kind of salt and the solubility of the polymer is reduced due to salting out. In such cases, not only is the polymer thickener's effect not exhibited but also the product has a fatal problem such as precipitation of the thickener over time.
In view of the aforementioned problem, the inventors conducted earnest research to discover that a composition comprising an anionic surfactant or ampholytic surfactant and hydrophobically modified polyether urethane which can associate in a water sobluble medium to increase the viscosity of the water soluble medium can solve the aforementioned problems and exhibits superior performance as a cleaning agent, thus completing the present invention.
The object of the present invention is to provide a cleaning agent composition that has superior viscosity and is superior in foam formation and foam durability, and feels refreshing without a slimy sensation after rinsing-off.